1. Field of the Invention
The present invention relates to a device for connecting two cables, together, the two cables being of the same or different diameters.
In some work sites, for example on sea drilling platforms anchored by cables, there is sometimes need to join two cables together, for example an anchorage cable to a cable of smaller diameter for handling the anchorage cable, and the connection of the two cables must on the one hand be capable of withstanding heavy tractive forces exerted on the cables and, on the other, sufficiently compact and flexible to be able to pass over one or more pulleys.
2. Description of the Prior Art
Up to now, for joining two cables together, it has been current practice to splice them by interlacing their strands and fixing the strands together by welding or brazing. However, with this method of joining, it is difficult to check the strength of the joint and in general a breaking strength can only be guaranteed which is about half that of the smallest diameter cable. Furthermore, such a method of joining presents a risk of breakage of the welds or at least weakening thereof when passing over a pulley. In addition, the splice thus obtained has only relatively small flexibility and a relatively large diameter, which hinders the passage of the joint over a pulley or necessitates the provision of a pulley having both a larger diameter and a groove substantially wider than the one which would be necessary for receiving the largest diameter cable.
Flexible connections for cables are known by German Pats. Nos. 1 900 909 and 1 169 731. In these known cable connecting devices, the end of each cable is provided with a pear shaped ferrule. Each ferrule comprises a first socket and a second socket detachably fixed to the first socket by a bayonet joint (German Pat. No. 1 900 909) or by a threaded coupling (German Pat. NO. 1 169 731). Each first socket forms a ball and socket joint with one of two partially spherical members fixed to the ends of a short linking rod, respectively. Each second socket has a funnel shape or the shape of a hollow cone with an axial passage receiving an end portion of one of the two cables to be connected, the wires of which are spread and embedded in a mass of metal cast in the passage of said second socket to secure said end portion of the cables to the corresponding second socket (see page 2, lines 27 to 29 and page 3, lines 12 to 14 in German Pat. No. 1 900 909 and column 4, lines 19 to 23 in German Pat. No. 1 169 731). Thus, said first and second sockets have an outer diameter which is much larger than that of the cables (about 41/2 times larger in the examples shown in these German patents).
U.K. Pat. No. 363 422 shows a device for connecting a wire rope to a chain. In this known device, the wire rope is secured to a socket by driving in a taper pin and by soldering (page 2, lines 65 to 67). The socket has a rounded end forming a ball and socket joint with a correspondingy rounded end of a thimble to which the chain is attached. Here again, the transversal dimension of the thimble, hence the largest transversal dimension of the connection is much larger than the outer diameter of the wire rope (more than four times larger in the example shown in this U.K. patent).